This is a visualization of a Look Ahead Left to Right with 1 look ahead token parser.
This implementation aims at parsing some input files found in ./data dir.
We will be using a CLR parsing table to do so. CLR stands for Canonical Left to Right parser.
Massiles GHERNAOUT. (github.com/Massigy)
For the data/input.txt file, we assume that the preprocessor is already passed by it.
So, we expect to have all the input text in one line and every token is seperated by a space from the previous one.
Also, each time you run the program, you'll see in the console the read tokens.
G :
(1) P → debut S fin
(2) S → IR
(3) R → ;IR
(4) R → ε
(5) I → id := E
(6) I → ε
(7) E → T E′
(8) E′ → +T E′
(9) E′ → ε
(10) T → F T ′
(11) T ′ → ∗F T ′
(12) T ′ → ε
(13) F → (E)
(14) F → id
(15) F → nb
nb stands for number.
id is a variable name like a,b,c...
debut is french for begin.
fin is french for end.
When the input does not follow the grammar. The input gets rejected and an error is raised with some hint for debugging.
When the input follows the grammar correctly. The input gets accepted.